1. Field of the Invention
The present invention relates to a magnetic circuit for use in a coaxial speaker, and more particularly, to a magnetic circuit that shares a common magnetic loop and is capable of providing a uniform magnetic field distribution, improving the voice coil driving efficiency and effectively reducing the overall size of the speaker.
2. Description of the Related Art
With increasing competitiveness in today's electronic product market, is becoming more competitive, every manufacturer requirements on the specifications of speaker for electronic products have become more critical than ever. Not only hope the speaker size to be more compact size to fit thin electronic product design, but also want the speaker to provide a wide range of audio output. It is therefore often necessary to install a second driver, promoting the creation of coaxial speaker.
Various coaxial speakers are known. For example, a conventional coaxial speaker 80 as shown in FIG. 1, which comprises a low range driver 81 and a mid-high range driver 82. The low range driver 81 and the mid-high range driver 82 respectively comprise an independent diaphragm 83 and an independent magnetic circuit 84. The mid-high range driver 82 is coaxially mounted in the center of an accommodation area within low range driver 81. However, because the two drivers are respectively disposed at different elevations and have different sizes, the overall thickness of this design of coaxial speaker 80 is greatly increased. Obviously, this design of coaxial speaker does not meet the requirements of the electronic market. Further, the magnetic lines of force of the magnet are emitted from the N pole to pass through the two opposite lateral sides of the magnet to the S pole thereof. However, a regular magnetic circuit simply uses the magnetic field at one lateral side of the magnet, as shown in FIG. 2, and a severe magnetic flux leakage can occur at the opposite lateral side. Therefore, an improvement in this regard is necessary.